+ 1 for fiji pink, bimini blue is nice also. but as most of the group said preference takes priority. as long as it is calcium carbonate base material you really cant go wrong. depth size etc are going to be based on your tank in my nano i use shallow 1 inch mixed crushed coral and fiji pink. in 75 i use 5 inch deep fiji sand bed with 1 inch of crushed coral on bottom with large eel, and soft coral. careful with colored subtrates make sure they will buffer the water.
The fiji pink that everyone is recommending is the perfect long term color and grain size for the tank. Anything bigger and any waste is going to filter through to the bottom of the sand, and anything finer you will have problems with sand storms.
That said, anything in that grain size will work, the rest is personal preference. I personally hate the black/white cichlid style sand because it reminds me of my cichlid tank and this is a SW tank. The whiter the sand the more you will curse when it starts to get darker due to coralline/dietrius.